Alle Firmen mit dem Anfangsbuchstaben I
- Ing. Hasenbichler Robert
- Ing. Hasenhütl Werner Peter
- Ing. Haslauer Gerald Alois
- Ing. Haslehner Christoph
- Ing. Hasler Mario Harald
- Ing. Hattenberger Karl
- Ing. Haubenhofer Gernot
- Ing. Hauder Oliver
- Ing. Hauer Christoph
- Ing. Hauer Michael
- Ing. Hauer Thomas
- Ing. Hauer Walter
- Ing. Haupert Manuel Josef
- Ing. Hausberger Wolfgang
- Ing. Hauser Georg
- Ing. Hauser Manfred
- Ing. Hauser Martin
- Ing. Hausl Markus
- Ing. Hausladen GmbH
- Ing. Haussl Peter
- Ing. Havekost Dorian
- Ing. Havlik Rudolf
- Ing. Hecht Martin
- Ing. Heegemann Elke
- Ing. Hehenberger Dominika
- Ing. Heidecker Stefan
- Ing. Heidenreich Rene
- Ing. Heigl & Partner GmbH
- Ing. Heiling Alexander
- Ing. Heilinger Christian
- Ing. Heilinger Josef
- Ing. Hein Thomas Reinhold
- Ing. Heinrich Mussmann, Baumeister
- Ing. Heinricher Clemens
- Ing. Heinsching Andreas
- Ing. Heinz Anton Kaiser Gerüsteverleih KG
- Ing. Heinzel Martin Ludwig
- Ing. Heissenberger Johannes
- Ing. Heiß Christian
- Ing. Heiß Jan
- Ing. Helbich Reinhard
- Ing. Hell Philipp
- Ing. Hellinger Roland Wolfgang
- Ing. Hellmann Kurt
- Ing. Helmut Berger GmbH
- Ing. Helmut Kurzweil GmbH
- Ing. Helmut Leitner e.U.
- Ing. Helmut Mayer Technisches Service e.U.
- Ing. Helmut Rathmayr, Persönlichkeits- und Unternehmensförderung
- Ing. Helmut Siebenhandl GmbH
- Ing. Helmut Stindl GmbH
- Ing. Helmuth Gradwohl und Mitbesitzer
- Ing. Helperstorfer Martin
- Ing. Hemetsberger Christian
- Ing. Hengsberger Johann
- Ing. Herbert Frana
- Ing. Herbert Gradl - Joy of Living Consulting
- Ing. Herbert Launoy Sachverständiger
- Ing. Herbert Mayrhuber Installationen GmbH
- Ing. Herbert PLASS KEG
- Ing. Herbert Staltner GmbH
- Ing. Herbert Wocilka, Dächer & Fassaden Ges.m.b.H.
- Ing. Herbert Übleis GmbH
- Ing. Herfurth Wolfgang
- Ing. Heribert Schnabl
- Ing. Hermann Mentil GmbH
- Ing. Hermann Poneder
- Ing. Hermann Walter
- Ing. Hernecek & Dipl.Ing. Rybnicek OEG IBU Ingenieurgemeinschaft Betrieb & Umwelt
- Ing. Herold Wolfgang
- Ing. Herzog Ludwig
- Ing. Hetych Heinz
- Ing. Hetzenauer Christian
- Ing. Heumader Gerold Manfred
- Ing. Hickersberger Frowalt
- Ing. Hiden Andreas
- Ing. Hiden Franz
- Ing. Hiebler Gerald
- Ing. Hiermann Alfred
- Ing. Hiessleitner Patrick